Attachment angle measuring device and attachment angle measuring method

Abstract

The present invention provides an attachment angle measuring device and an attachment angle measuring method which realize accurate measurement of attachment angle between an axle carrier and an absorber. An attachment angle measuring device measures an attachment angle θ between an axle carrier and an absorber as in the following. A slit light is projected to a first reflection position on an outer peripheral surface of an absorber rod and a reflected light from the first reflection position is received. A slit light is projected to a second reflection position on the outer peripheral surface of the absorber rod different from the first reflection position and a reflected light from the second reflection position is received. A first optical path distance between a projection start position of the slit light and the first reflection position is calculated based on the reflected light. A second optical path distance between the projection start position of the slit light and the second reflection position is calculated based on the reflected light. Based on the first optical path distance and the second optical path distance, attachment angle θ is calculated.

1. An attachment angle measuring device measuring an attachment angle between an axle carrier rotatably supporting a wheel and an absorber comprising an absorber main body attached to the axle carrier and an absorber rod slidably inserted into the absorber main body, comprising:
 a first light projecting part projecting a light to a first reflection position on an outer peripheral surface of the absorber rod when the axle carrier is fixed at a predetermined measurement position, the absorber is attached to the axle carrier and the absorber rod does not contact any member except the axle carrier; 
 a first light receiving part receiving the reflected light from the first reflection position; 
 a second light projecting part projecting a light to a second reflection position different from the first reflection position on the outer peripheral surface of the absorber rod when the axle carrier is fixed at the predetermined measurement position, the absorber is attached to the axle carrier and the absorber rod does not contact any member except the axle carrier; 
 a second light receiving part receiving the reflected light from the second reflection position; 
 a first optical path distance calculating part calculating a first optical path distance between the first light projecting part and the first reflection position based on the reflected light received by the first light receiving part; 
 a second optical path distance calculating part calculating a second optical path distance between the second light projecting part and the second reflection position based on the reflected light received by the second light receiving part; and 
 an attachment angle calculation part calculating the attachment angle between the axle carrier and the absorber based on the first optical path distance and the second optical path distance. 
 
     
     
       2. The attachment angle measuring device as set forth in  claim 1 , wherein
 the first light projecting part and the second light projecting part project a slit light to the absorber rod, 
 the first optical path distance calculating part generates a first profile of the outer peripheral surface of the absorber rod based on the reflected light received by the first light receiving part and regards a point which is the closest to the first light projecting part on the first profile as the first reflection position so as to calculate the first optical path distance, and 
 the second optical path distance calculating part generates a second profile of the outer peripheral surface of the absorber rod based on the reflected light received by the second light receiving part and regards a point which is the closest to the second light projecting part on the second profile as the second reflection position so as to calculate the second optical path distance. 
 
     
     
       3. The attachment angle measuring device as set forth in  claim 2 , wherein
 the first optical path distance calculating part generates a first correction profile by correcting the first profile as a circular arc or an elliptical arc, and a point which is the closest to the first light projecting part on the first correction profile is regarded as the first reflection position so as to calculate the first optical path distance, and 
 the second optical path distance calculating part generates a second correction profile by correcting the second profile as a circular arc or an elliptical arc, and a point which is the closest to the second light projecting part on the second correction profile is regarded as the second reflection position so as to calculate the second optical path distance. 
 
     
     
       4. The attachment angle measuring device as set forth in  claim 1 , wherein the attachment angle calculation part calculates the attachment angle θ between the axle carrier and the absorber by substituting a difference ΔH between the distance between the axis of the fixed axle carrier and the first light projecting part and the distance between the axis of the fixed axle carrier and the second light projecting part and the first optical path distance L 1  and the second optical path distance L 2  for a below Numerical Formula 1. 
       
         
           
             
               
                 
                   
                     θ 
                     = 
                     
                       
                         
                           tan 
                           
                             - 
                             1 
                           
                         
                         ⁡ 
                         
                           ( 
                           
                             
                               Δ 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               H 
                             
                             
                               
                                 L 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                               - 
                               
                                 L 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 1 
                               
                             
                           
                           ) 
                         
                       
                       . 
                     
                   
                 
                 
                   
                     [ 
                     
                       Numerical 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       Formula 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       1 
                     
                     ] 
                   
                 
               
             
           
         
       
     
     
       5. The attachment angle measuring device as set forth in  claim 1 , further comprising an axle carrier fixation part detachably fixing the axle carrier to the measurement position. 
     
     
       6. The attachment angle measuring device as set forth in  claim 5 , further comprising an absorber fixation part detachably fixing the absorber at a position at which the absorber can be attached to the axle carrier fixed by the axle carrier fixation part. 
     
     
       7. The attachment angle measuring device as set forth in  claim 6 , wherein the absorber fixation part fixes the absorber at a posture at which the attachment angle between the axle carrier fixed by the axle carrier fixation part and the absorber is within a predetermined angular range. 
     
     
       8. An attachment angle measuring method measuring an attachment angle between an axle carrier rotatably supporting a wheel and an absorber comprising an absorber main body attached to the axle carrier and an absorber rod slidably inserted into the absorber main body, comprising:
 a fixing process in which the axle carrier to which the absorber is attached is fixed at a measurement position set previously; 
 a first light projecting and receiving process in which the absorber attached to the axle carrier fixed at the measurement position is kept not contacting anything except the axle carrier, and a light is projected to a first reflection position on an outer peripheral surface of the absorber rod of the absorber and the reflected light from the first reflection position is received; 
 a second light projecting and receiving process in which the absorber attached to the axle carrier fixed at the measurement position is kept not contacting anything except the axle carrier, and a light is projected to a second reflection position on an outer peripheral surface of the absorber rod of the absorber different from the first reflection position and the reflected light from the second reflection position is received; 
 a first optical path distance calculating process which calculates the first optical path distance between the projection start position in the first light projecting and receiving process and the first reflection position based on the reflected light received in the first light projecting and receiving process; 
 a second optical path distance calculating process which calculates the second optical path distance between the projection start position in the second light projecting and receiving process and the second reflection position based on the reflected light received in the second light projecting and receiving process; and 
 an attachment angle calculating process in which the attachment angle between the axle carrier and the absorber is calculated based on the first optical path distance and the second optical path distance. 
 
     
     
       9. The attachment angle measuring method as set forth in  claim 8 , wherein
 in each of the first light projecting and receiving process and the second light projecting and receiving process, a slit light is projected to the absorber rod, 
 in the first optical path distance calculating process, a first profile of the outer peripheral surface of the absorber rod is generated based on the reflected light received in the first light projecting and receiving process and a point which is the closest to the projection start position in the first light projecting and receiving process on the first profile is regarded as the first reflection position so as to calculate the first optical path distance, and 
 in the second optical path distance calculating process, a second profile of the outer peripheral surface of the absorber rod is generated based on the reflected light received in the second light projecting and receiving process and a point which is the closest to the projection start position in the second light projecting and receiving process on the second profile is regarded as the second reflection position so as to calculate the second optical path distance. 
 
     
     
       10. The attachment angle measuring method as set forth in  claim 9 , wherein
 in the first optical path distance calculating process, a first correction profile is generated by correcting the first profile as a circular arc or an elliptical arc, and a point which is the closest to the projection start position in the first light projecting and receiving process on the first correction profile is regarded as the first reflection position so as to calculate the first optical path distance, and 
 in the second optical path distance calculating process, a second correction profile is generated by correcting the second profile as a circular arc or an elliptical arc, and a point which is the closest to the projection start position in the second light projecting and receiving process on the second correction profile is regarded as the second reflection position so as to calculate the second optical path distance. 
 
     
     
       11. The attachment angle measuring method as set forth in  claim 8 , wherein in the attachment angle calculating process, the attachment angle between the axle carrier and the absorber is calculated by substituting the difference ΔH between the distance between the axis of the axle carrier fixed at the measurement position and the projection start position in the first light projecting and receiving process and the distance between the axis of the axle carrier fixed at the measurement position and the projection start position in the second light projecting and receiving process and the first optical path distance L 1  and the second optical path distance L 2  for a below Numerical Formula 1. 
       
         
           
             
               
                 
                   
                     θ 
                     = 
                     
                       
                         
                           tan 
                           
                             - 
                             1 
                           
                         
                         ⁡ 
                         
                           ( 
                           
                             
                               Δ 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               H 
                             
                             
                               
                                 L 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                               - 
                               
                                 L 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 1 
                               
                             
                           
                           ) 
                         
                       
                       . 
                     
                   
                 
                 
                   
                     [ 
                     
                       Numerical 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       Formula 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       1 
                     
                     ] 
                   
                 
               
             
           
         
       
     
     
       12. The attachment angle measuring method as set forth in  claim 8 , wherein the fixing process comprises:
 an axle carrier fixing process in which the axle carrier is fixed at the measurement position; and 
 an absorber attaching process in which the absorber is attached to the axle carrier fixed at the measurement position in the axle carrier fixing process.